Separating techniques Flashcards
Separating by particle size
Sieving
gravitational filtration
Vacuum filtration
Sieving
You use a strainer and pour the sand and water into it and it catches the solid
Gravitational filtration
Rely on weight of solid particle to filter the two materials (wait for sand to settle to bottom)
What is filtration
Used to separate an insoluble substance from a soluble substance
Uses porous barrier to separate the solid from liquid
What mixtures are used with filtration
Used to separate heterogeneous mixtures composed of solids and liquids
Separation by density
You can use
Sedimentation/decantation
Separation funnel
Centrifugation
Sedimentation-Decantation
Sedimentation is where the more dense material sinks to the bottom of the substance and decantation is when you pour out the liquid at the surface
Separation funnel
Can be used when liquids dont mix. Tap at the bottom and you can let most the dense material out
Centrifugation
When we spin a mixture in a centrifuge, this helps to settle finer particles that may not settle naturally
Separation by boiling point
Evaporation
Distillation
Fractional distillation
Evaporation
Is where you boil off the solvent and it leaves the dissolved material (solute) behind
Distillation
Uses evaporation but also collects the gas in a condenser and convers that back into liquid
Fractional distillation
Used for mixtures that have many different substances in them, that all have slightly different boiling points (All heated and all will be in layers based on their boiling points)
When is distillation and evaporation
Used to separate homogeneous mixtures
Crystallisation
Technique that results in the formation of pure solid particles from a solution containing the dissolved substance.
As one substance evaporated the dissolved substance comes out of the solution as crystals
